This invention relates to shaft seals, and more particularly to structures for accommodating radial shaft movements associated with runout and mis-alignment eccentricities.
Numerous prior art sealing designs are provided for conditions of high shaft runout and mis-alignment in environments such as crankcase housing bores having shafts extending therefrom. When severe, such conditions cause premature failures of typical sealing systems. Many designs include flexible sections which connect lip type sealing elements with rigid case supports normally affixed to the housing bores. The flexible sections provide a floating capability with respect to the sealing lip for permitting radial movement of a shaft relative to the rigid case support without severe leakage, particularly where extreme eccentricities allow for high shaft runouts over substantial periods of time.
Most of these systems, however, lack stability under extreme runout conditions, wherein, notwithstanding the flexibility of the connective member between the rigid case support and the lip sealing element, there is a need to control or at least curtail some of the dynamic movement associated with the flexible portion. Such control of dynamic seal lip movement would enhance lip contact with the shaft.